Genetic Distance Coefficients Research Articles

Genetic diversity and population structure of Chinese natural bermudagrass [Cynodon dactylon (L.) Pers.] germplasm based on SRAP markers.

Bermudagrass [Cynodon dactylon (L.) Pers.], an important turfgrass used in public parks, home lawns, golf courses and sports fields, is widely distributed in China. In the present study, sequence-related amplified polymorphism (SRAP) markers were used to assess genetic diversity and population structure among 157 indigenous bermudagrass genotypes from 20 provinces in China. The application of 26 SRAP primer pairs produced 340 bands, of which 328 (96.58%) were polymorphic. The polymorphic information content (PIC) ranged from 0.36 to 0.49 with a mean of 0.44. Genetic distance coefficients among accessions ranged from 0.04 to 0.61, with an average of 0.32. The results of STRUCTURE analysis suggested that 157 bermudagrass accessions can be grouped into three subpopulations. Moreover, according to clustering based on the unweighted pair-group method of arithmetic averages (UPGMA), accessions were divided into three major clusters. The UPGMA dendrogram revealed that accessions from identical or adjacent areas were generally, but not entirely, clustered into the same cluster. Comparison of the UPGMA dendrogram and the Bayesian STRUCTURE analysis showed general agreement between the population subdivisions and the genetic relationships among accessions. Principal coordinate analysis (PCoA) with SRAP markers revealed a similar grouping of accessions to the UPGMA dendrogram and STRUCTUE analysis. Analysis of molecular variance (AMOVA) indicated that 18% of total molecular variance was attributed to diversity among subpopulations, while 82% of variance was associated with differences within subpopulations. Our study represents the most comprehensive investigation of the genetic diversity and population structure of bermudagrass in China to date, and provides valuable information for the germplasm collection, genetic improvement, and systematic utilization of bermudagrass.

Sequence-related amplified polymorphism and inter-simple sequence repeat marker-based genetic diversity and nuclear DNA content variation in common vetch (Vicia sativaL.)

Genetic diversity of 30 common vetch (Vicia sativaL.) lines and cultivars obtained from various resources or collected from natural flora of Turkey was evaluated by using 55 sequence-related amplified polymorphism (SRAP) and five inter-simple sequence repeat (ISSR) primer sets, and their nuclear DNA contents were determined by flow cytometer. A total of 188 polymorphic loci were detected, with an average of 3.62 loci per primer. The percentage of polymorphic loci was 82.1%. The polymorphism information content values ranged from 0.12 to 0.96, with an average of 0.63. The genetic distance coefficients were in the range of 0.112–0.627. Cluster analysis revealed that the 27 lines and three cultivars could be divided into two main groups. No polyploidy was detected within any vetch lines tested while significant (P< 0.0001) nuclear DNA content differences were determined. The present study revealed that fast and accurate fingerprinting analysis could be done using SRAP and ISSR markers, which indicated existing significant variation among common vetch lines and cultivars.

Genetic characterization of microsporidians infecting Indian non-mulberry silkworms (Antheraea assamensis and Samia cynthia ricini) by using PCR based ISSR and RAPD markers assay

This study established the genetic characterisation of 10 microsporidian isolates infecting non-mulberry silkworms (Antheraea assamensis and Samia cynthia ricini) collected from biogeographical forest locations in the State of Assam, India, using PCR-based markers assays: inter simple sequence repeat (ISSR) and random amplified polymorphic DNA (RAPD). A Nosema type species (NIK-1s_mys) was used as control for comparison. The shape of mature microsporidian spores were observed oval to elongated, measuring 3.80 to <TEX>$4.90{\mu}m$</TEX> in length and 2.60 to <TEX>$3.05{\mu}m$</TEX> in width. Fourteen ISSR primers generated reproducible profiles and yielded 178 fragments, of which 175 were polymorphic (98%), while 16 RAPD primers generated reproducible profiles with 198 amplified fragments displaying 95% of polymorphism. Estimation of genetic distance coefficients based on dice coefficients method and clustering with un-weighted pair group method using arithmetic average (UPGMA) analysis was done to unravel the genetic diversity of microsporidians infecting Indian muga and eri silkworm. The similarity coefficients varied from 0.385 to 0.941 in ISSR and 0.083 to 0.938 in RAPD data. UPGMA analysis generated dendrograms with two microsporidian groups, which appear to be different from each other. Based on Euclidean distance matrix method, 2-dimensional distribution also revealed considerable variability among different identified microsporidians. Clustering of these microsporidian isolates was in accordance with their host and biogeographic origin. Both techniques represent a useful and efficient tool for taxonomical grouping as well as for phylogenetic classification of different microsporidians in general and genotyping of these pathogens in particular.

느티만가닥버섯에서 감마선에 의한 돌연변이체들의 유전적 변이

This research was carried out to evaluate whether gamma ray is a useful tool for breeding new strains of mushrooms. For this research, 5 mutant groups, 20 strains of Hypsizigus marmoreus, 2 strains of Lyophyllum decastes, and 1 strain of Lyophyllum shimeji were used. Monokaryon spores from one variety of H. marmoreus were irradiated with 50~2,000 Gy of gamma ray. The propriety dose was 50~200 Gy for mutagenesis. Mutant monokaryon mycelia crossed each order to become dikaryon mycelia. The internal transcribed spacer (ITS) regions of rDNA were amplified using PCR, and the products were sequenced. The sequences of the ITS regions (16 partial rDNA, complete ITS1, 5.8 rDNA and partial rDNA) were analyzed by PCR, and strains of H. marmoreus, L. decastes, and L. shimeji were auto- sequenced. The lengths of the sequenced ITSs were 1,052~1,143 nucleotides. Genetic matrices were cal-culated using Nei-Li's genetic distance coefficient based on ITS sequence. The dissimilarities were 0~3.35% in strains of H. Hypsizigus. In addition, a phylogenetic tree was constructed based on ITS se-quences using the neighbor-joining (NJ) method. The phylogenetic tree revealed that 23 strains and 5 mutant groups were divided into 12 clusters; the mutant groups fell into different clusters. These results show that mushroom spores were mutated effectively by gamma ray; therefore, gamma ray could be a useful tool for breeding new strains of mushrooms.

Genetic Variability Evaluation among Iraqi ( Oryza Sativa L ) Varieties Using RAPD Markers and Protein Profiling

Genetic variability and relationships among ten rice varieties were studied by using 20 decamer random primers and SDSPAGE methods. Out of 22, 20 Random Amplified Polymorphic DNA (RAPD) primers revealed polymorphism, while the remaining 2 primers showed no reaction. The primers produced a total of 109 bands, of which 62 (56.88%) were polymorphic. The number of polymorphic fragments for each primer varied from 1 to 9 with an average of 3.1 polymorphic fragments. The primer OPC-07 produced the maximum number of polymorphic bands. The RAPD data were analyzed to determine the genetic distance coefficients which ranged from 0.30 to 0.76. Cluster analysis was performed using the Jaccard’s coefficient. The dendrogram resolved the selected rice varieties into four major clusters. On the other hand, similar varieties of rice were analyzed for endosperm storage proteins by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) to estimate their genetic diversity. Seed storage profiling led to the detection of a total of 12 polypeptide bands. The molecular weights of peptides ranged from 284 to 11 kDa. Polymorphism was not evident in all seed proteins of diverse molecular weights among all rice varieties, but two polymorphic bands (63 and 120 kDa) were found in a high molecular weight region. The results of the genetic diversity, obtained during this study, will be useful for the selection of the parents for developing rice breeding varieties in the future.

Cisovka - the relic population of Abies alba and its relationship to man-made silver-fir stands in Białowieża primeval forest

In Białowieża Primeval Forest, in 1823 Stanisław Górski discovered on the Cisovka Hag, a relic population of European silver-fir (&lt;em&gt;Abies alba&lt;/em&gt; Mill.). This population is isolated and most away, 120 km to the North-East, from the border of European-silver-fir distribution. Besides the natural population Cisovka, there are also man-made silver fir stands and clumps in the Polish and Belorussian part of Białowieża Primeval Forest. In the Polish part there are four such artificial stands. If the seed-producing silver-fir stands really originated from the Cisovka population, then they are a very valuable part of the declining population and an easy accessible seed source. However, if these populations were introduced to the Białowieża Primeval Forest, then they are a potential source of dangerous genetic pollution of the Cisovka population. The relationship of the genetic structure of the Cisovka population to man-made silver-fir-stands in Białowieża Forest was investigated with the help of 17 loci of 1 1 enzyme systems. Genetic diversity of Cisovka population is characterized by the smallest mean number of alleles per locus (&lt;em&gt;Mal&lt;/em&gt;= 1.353, includes all loci studied and per polimorphic locus &lt;em&gt;Malp&lt;/em&gt; = 2.00). In Cisovka population there is very low-grade of polimorphic loci (&lt;em&gt;Pp&lt;/em&gt; = 11.765 with the mean 37.255 for all studied populations). Expected heterozygosity, He = 0.079 revealed very low-grade of genetic diversity in the population. The observed heterozygosity (Ho = 0.123) was similar to this characterictic in other populations. A dendrogram based on Neis genetic distance coefficient (D) among 9 silver-fir populations was constructed. Cisovka in the UPGMA dendrogram is a distinct population separated from other ones by a very great genetic distance (D = 0.06). Also two man-made silver-fir (B I and 132) stands are separated from others. Only populations B3 and B4 are combined into one subgroup linked to the population Tomaszów Lubelski. Basing on the received results one should decide that all the four studied artificial stands were introduced to Białowieża Primeval Forest from beyond of this geographical regions. There is some reason to assume (on the GDH2 allele frequency) that man-made silver-stands in compartments 453Aa and 498Cg are of eastern provenance. It is rather certain that these stands are not of offspring of Cisovka populations.

Genetic Diversity of Chinese and CIP Potato (Solanum tuberosum L.) Germplasm Assessed by Amplified Fragment Length Polymorphism (AFLP) Markers

The genetic diversity of 123 potato clones, consisting of 103 clonal accessions from the International Potato Center (CIP) and 20 Chinese cultivars, was assessed using amplified fragment length polymorphism (AFLP) markers. Ten polymorphic primer combinations were selected to analyse and compare the diversity of the two sources of clones. A total of 521 reproducible bands were amplified, of which 488 were polymorphic. These AFLP markers were analysed to estimate the genetic distance (GD) and genetic similarity (GS) coefficient of all clones. The GD between pairs of clones ranged from 0.03 to 0.48. Nei’s gene diversity index was between 0.236 and 0.387, with an average of 0.330. The index of Shannon’s information varied from 0.361 to 0.567 with an average of 0.498. A high degree of polymorphism was observed with an average of 93.6% loci found to be polymorphic. Cluster analysis showed that the CIP accessions were grouped together at the GS 0.59 clustering line, whereas most Chinese cultivars grouped at the GS 0.82 clustering line. The diversity in CIP potato resources was found to be higher than that of the Chinese cultivars, indicating that the genetic base of Chinese potato cultivars is narrow and may benefit from broadening.

Rozlíšenie Idt a SSS populácií kukurice siatej (Zea mays, L) ISSR markérmi

Maintaining genetic diversity for crop improvement and improving the quality of genetic resource management is both an inevitable part of nowadays maize breeding. ISSR markers brings the potential of finding a marker system to discriminate Iowa Stiff Stalk Synthetic and Iodent Reid populations of Zea mays, L. and on the base on coefficients of genetic distance and UPGMA grouping appropriate maize genotypes for the best potential for hybridization can be selected. The work presents the potential of ISSR markers in analysis of length polymorphism when a specific ISSR pattern can be used for fast screening of differences among maize genotypes and based of these differences lines can be used in breeding programms in a very specific mode.

Physiological and Protein Responses to Drought in Four Pine Seedlings

Abstract Physiological and protein responses to drought stress in four pine seedlings, Pinus armandi Franch. (Pa), Pinus tabulaeformis Carr. (Pt), Pinus bungeana Zucc. ex Endl. (Pb) and Pinus sylvestris L. var. mongolica Litv. (Ps), were investigated using differential proteomics and water physiological indices. Firstly, the water physiological data showed that the decline rate of net photosynthesis rate, stomatal conductance, leaf water potential, turgor pressure except for under moderate drought stress was as follows: Pa&gt;Ps&gt;Pt&gt;Pb. Pb and Pa always maintained the highest and lowest swelling pressure, respectively. Secondly, cluster analysis of 343 proteins indicated that the four pine species were classified into three groups with a genetic distance coefficient of 0.065. That is, five-needle-pine group (Pa), three-needle-pine group (Pb), two-needle-pine group (Pt and Ps), and the genetic distance between Pb and Pa was the farthest. The result was consistent with the declined rate in above physiological indices. Finally, for the differential proteomics analyzed, a total of 13 different proteins (P values &lt; 0.01) changed significantly, the number of differentially expressed proteins was more in Pa (accounting for 46.2%) than the other three species, and 8 proteins were identified using matrix-assisted laser desorption/ionization time -of-flight mass spectrometry (MALDI-TOF-MS). These proteins are quite diverse in their functions and involved in photosynthesis, osmotic regulation and functioning as signal transduction. These results suggested that the sensitivities of the four pine species to drought were possibly related to genetic distance.

Assessment of genetic variation in Russian olive (Elaeagnus angustifolia) based on morphological traits and random amplified polymorphic DNA (RAPD) genetic markers

In this study, a combination of random amplification of polymorphic deoxyribonucleic acid (RAPD) marker and morphological traits were used to establish the level of genetic relationships and polymorphism among nine genotypes of Elaeagnus angustifolia collected from 9 different locations of West Azarbaijan province. RAPD analysis using 9 random primers generated 122 scorable loci, of which 103 were polymorphic (84.4%). The estimated Jaccard’s similarity coefficient ranged from 0.36 to 0.62 for RAPD marker. The cluster analysis was performed based on Unweighted Pair Group Method with Arithmetic Averages (UPGMA) and dendrogram plotted by help of NTSYSpc 2.02 software. The analysis revealed 4 main clusters for RAPD data. In morphological part, 20 traits were studied. Data analysis was carried out using NTSYSpc 2.02 software and genetic distance matrix obtained by MANHAT coefficient. Genetic distance coefficient ranged from 0.30 to 0.95 for morphological analysis. The dendrogram was plotted by help of UPGMA method in SAHN program and revealed 4 main clusters. According to our results, relatively high genetic distance among E. angustifolia genotypes suggests that E. angustifolia can be classified into subspecies level in West Azarbaijan province. Furthermore, it could be inferred that RAPD markers and morphological traits are suitable tools for evaluation of genetic diversity and relationships within E. angustifolia. Key words: Dendrogram, Elaeagnus angustifolia, genetic variation, morphological traits, RAPD genetic marker.

Diversity and relationships between coefficient of parentage and genetic distance estimated by SSR markers in Japanese rice cultivars

Diversity and relationships between coefficient of parentage and genetic distance estimated by SSR markers in Japanese rice cultivars

Molecular characterization of diverse CIMMYT maize inbred lines from eastern and southern Africa using single nucleotide polymorphic markers

BackgroundKnowledge of germplasm diversity and relationships among elite breeding materials is fundamentally important in crop improvement. We genotyped 450 maize inbred lines developed and/or widely used by CIMMYT breeding programs in both Kenya and Zimbabwe using 1065 SNP markers to (i) investigate population structure and patterns of relationship of the germplasm for better exploitation in breeding programs; (ii) assess the usefulness of SNPs for identifying heterotic groups commonly used by CIMMYT breeding programs; and (iii) identify a subset of highly informative SNP markers for routine and low cost genotyping of CIMMYT germplasm in the region using uniplex assays.ResultsGenetic distance for about 94% of the pairs of lines fell between 0.300 and 0.400. Eighty four percent of the pairs of lines also showed relative kinship values ≤ 0.500. Model-based population structure analysis, principal component analysis, neighbor-joining cluster analysis and discriminant analysis revealed the presence of 3 major groups and generally agree with pedigree information. The SNP markers did not show clear separation of heterotic groups A and B that were established based on combining ability tests through diallel and line x tester analyses. Our results demonstrated large differences among the SNP markers in terms of reproducibility, ease of scoring, polymorphism, minor allele frequency and polymorphic information content. About 40% of the SNPs in the multiplexed chip-based GoldenGate assays were found to be uninformative in this study and we recommend 644 of the 1065 for low to medium density genotyping in tropical maize germplasm using uniplex assays.ConclusionsThere were high genetic distance and low kinship coefficients among most pairs of lines, clearly indicating the uniqueness of the majority of the inbred lines in these maize breeding programs. The results from this study will be useful to breeders in selecting best parental combinations for new breeding crosses, mapping population development and marker assisted breeding.

Assessing genetic divergence in interspecific hybrids of Aechmea gomosepala and A. recurvata var. recurvata using inflorescence characteristics and sequence-related amplified polymorphism markers

Conventional hybridization and selection techniques have aided the development of new ornamental crop cultivars. However, little information is available on the genetic divergence of bromeliad hybrids. In the present study, we investigated the genetic variability in interspecific hybrids of Aechmea gomosepala and A. recurvata var. recurvata using inflorescence characteristics and sequence-related amplified polymorphism (SRAP) markers. The morphological analysis showed that the putative hybrids were intermediate between both parental species with respect to inflorescence characteristics. The 16 SRAP primer combinations yield 265 bands, among which 154 (57.72%) were polymorphic. The genetic similarity was an average of 0.59 and ranged from 0.21 to 0.87, indicating moderate genetic divergence among the hybrids. The unweighted pair group method with arithmetic average (UPGMA)-based cluster analysis distinguished the hybrids from their parents with a genetic distance coefficient of 0.54. The cophenetic correlation was 0.93, indicating a good fit between the dendrogram and the original distance matrix. The two-dimensional plot from the principal coordinate analysis showed that the hybrids were intermediately dispersed between both parents, corresponding to the results of the UPGMA cluster and the morphological analysis. These results suggest that SRAP markers could help to identify breeders, characterize F(1) hybrids of bromeliads at an early stage, and expedite genetic improvement of bromeliad cultivars.

Genetic Diversity and Population Structure of Ethiopian Chickpea (Cicer arietinum L.) Germplasm Accessions from Different Geographical Origins as Revealed by Microsatellite Markers

Genetic diversity and population structure were studied in 155 chickpea (Cicer arietinum L.) entries using 33 polymorphic microsatellite (SSR) markers. Molecular analysis of variance showed variations of 73% within and 27% among populations. Introduced genotypes exhibited highest polymorphism (70.27%) than the landraces (36–57%). Collections from Shewa, Harerge, W. Gojam and S. Gonder regions also showed higher polymorphism (50–57%) than the rest of the local accessions (36–45%). Analyses of pairwise population Nei genetic distance and PhiPT coefficients, expected heterozygosity (He) and unbiased expected heterozygosity (UHe), Shannon’s information index (I) and percent polymorphism (% P) showed existence of high genetic variation between geographical regions. Accessions from adjoining geographical regions mostly showed more genetic similarities than those from origins far isolated apart. This could be associated with the ease and likelihood of inter-regional gene flow and seed movement particularly during times of drought. The 155 entries were grouped into five clusters following analysis of population structure. The first cluster (C1) constituted accessions from Arsi; the second (C2) from Gojam and Gonder; the third (C3) from Harerge and E. and N. Shewa; and the fourth (C4) from W. Shewa, Tigray, and Wello regions. The fifth cluster (C5) was entirely consisted of improved genotypes. Improved genotypes of both Kabuli and Desi types distinctly fell into cluster five (C5) regardless of their difference in seed types. The result has firmly established that introduction of genetic materials from exotic sources has broadened the genetic base of the national chickpea breeding program. Further implications of the findings as regards to chickpea germplasm management and its utilization in breeding program are also discussed.

GENETIC DIVERSITY ASSOCIATED WITH AGRONOMIC TRAITS AND BIOTIC STRESSES USING SSR MARKERS IN SOME EGYPTIAN RICE GENOTYPES

Genetic diversity underlies the improvement of crops by plant breeding. In Egypt, pedigree analyses indicate that the rice varieties currently under cultivation are closely related in there genetic background. Effective breeding programs, based on the information about of the genetic diversity of cultivars, are needed to broaden the genetic bases of local rice germplasm in the country. The present study has been conducted to evaluate the pattern, type and extent of genetic variability and relatedness among some rice varieties and new promising lines of Egypt based on important agronomic traits and some biotic stresses of some common diseases using simple-sequence-repeat (SSR) markers. In this study, we used a set of twelve SSR markers to assess the genetic diversity of 22 Egyptian rice cultivars and new promising lines, which released by the National Rice Breeding Program between years of 1975 and 2010. The 12 microsatellite markers used in this study produced a total of 73 alleles. The number of alleles per marker ranged from 3 (RM282) to 9 (RM488), with an average of 6.08. The polymorphism information content (PIC) values were high for all microsatellites with average of 0.588 and ranged from a low of 0.345 for RM249 to a high of 0.716 for RM488 and RM144. UPGMA-cluster-analysis based on genetic distance coefficients clearly separated all the genotypes, and showed that the Egyptian rice varieties are closely related. Although the genetic diversity was low, SSRs proved to be an efficient tool in assessing the genetic diversity of rice genotypes. Implications of the low genetic diversity detected and relative relationship among Egyptian varieties are discussed. Varieties like Giza177, Sakha 102 and Sakha 103 are still resistant for most of the biotic stresses and become good sources for biotic stress resistance relating to different disease blast in the national breeding program.

Analysis of the genetic diversity in Saccharum spontaneum L. accessions from Guangxi Province of China with RAPD-PCR

Random amplified polymorphic DNA (RAPD)-PCR was employed to analyze the genetic diversity within 89 Saccharum spontaneum accessions collected from five different ecological regions of Guangxi Province, China. Of the 87 bands generated by nine RAPD primers, 96.6% were polymorphic. A substantial degree of genetic diversity was found among the locally collected S. spontaneum accessions. Pairwise genetic distance coefficients between accessions ranged from 8.6% (between accessions 87-10 and Yunge ③) to 74.2% (between accessions 87-31 and 85-53) with an average of 39.9%. Based on these genetic distance coefficients, the 89 S. spontaneum accessions were clustered into four groups irrespective of their ecological regions using the Cluster program of SAS (V8) software. Information from the present study would be useful for the conservation of locally collected S. spontaneum germplasm and exploitation of its genetic potential during sugarcane crossing program.

Characterization of Ugandan Sweetpotato Germplasm Using Fluorescent Labeled Simple Sequence Repeat Markers

The genetic relationships among 192 superior, high–yielding, and disease-resistant sweetpotato [Ipomoea batatas (L.) Lam] accessions from the Ugandan germplasm collection were analyzed using 10 fluorescent labeled simple sequence repeat (SSR) markers. Relatedness among the genotypes was estimated using the Nei and Li genetic distance coefficient, cluster analysis and principle component analysis methods of NTSYS-pc software. The polymorphic information content of the SSR markers used in this study ranged from 0.23 to 0.76 for loci IB-S07 and IB-R12, respectively, with a mean value of 0.62. The number of polymorphic alleles detected per locus ranged from two to six with a mean of four, a confirmation of the effectiveness of microsatellite detection on an automated ABI 3730 sequencer. The mean pairwise genetic distance among the 192 genotypes was 0.57, an indication of moderately high genetic diversity. Cluster analysis divided the accessions into four major groups with no relationship to the district of origin. Two sets of duplicates were identified through SSR genotyping in this study. Up to 190 distinct accessions for use as potential parental genotypes in hybridization schemes for cultivar development in the region were identified.

RAPD analysis for genetic diversity of medicinal plant Coptis omeiensis

To discuss the genetic diversity of Coptis omeiensis. The genetic diversity of 110 individuals from 10 populations was analyzed by RAPD. 14 primers were selected to produce highly reproducible RAPD bands. Among 132 amplified bands, 98 showed polymorphism, the percentage of polymorphic bands reached to 74.24%. Nei's gene diversity index (H) was 0.2863, Shannon's information index (I) was 0.3624, G(st) was 0.2305. The genetic distance coefficient and the similarity were 0.1931-0.5245 and 0.5016-0.8843, respectively. There exists a held high genetic diversity in C. omeiensis and the majority of genetic variation occurs in the populations. By cluster analysis, the geographical distribution is very obvious. The RAPD marker can be used for the analysis of the genetic diversity and genetic variation of C. omeiensis.

RAPD characterization of Corticium salmonicolor causing pink disease of trees

Corticium salmonicolor, fungal pathogen causing pink disease has a wide host range affecting major economically important tree species such as mango, orange, tea, coffee, eucalypts, acacias, rubber and teak. Because of its world-wide distribution, continued attention is paid towards host range, biology and genetic diversity of the pathogen. The present study was undertaken to determine the degree of genetic variation in five random isolates of C. salmonicolor. RAPD analysis was carried out using 10 selected primers; 102 RAPD loci and 50 per cent polymorphism were observed among the loci. Genetic distance coefficients between the isolates varied from 0.124 to 0.187. Mantel test did not reveal significant correlation between geographic distance of pathogen origin and genetic distance. RAPD genotype clustering was not in agreement with geographic isolation. The increased incidence of pink disease on tree crops and low genetic diversity of pathogens reveals the importance of further studies for a better understanding of genetic variability of this fungal pathogen in order to develop appropriate disease control measures.

Multivariate Quantitative Genetics of Anthropometric Traits from the Boas Data

The use of multivariate quantitative trait information to address questions of population relationships and evolutionary issues has a longstanding history in human anthropometry. Previous analyses have usually rested on a number of explicit or implicit assumptions that allow phenotypic information to be used as a proxy for quantitative genetic information. One (usually implicit) assumption is that the additive genetic variance-covariance matrix (G) among traits is proportional to the phenotypic variance-covariance matrix (P). In this study we discuss the implications of this assumption, demonstrating that if it is true that G = h 2 P, where h 2 is some constant of proportionality, then (1) the biological (phenotypic) Mahalanobis distance will be proportional to genetic distance, (2) phenotypic and genetic allometry coefficients will be equal, and (3) evolutionary models will become simplified. We then use a multivariate quantitative genetic analysis of 12 anthropometric traits in 5 tribes to demonstrate that G = h 2 P for at least a portion of the Boas data.